Question

The electrical conductivity of a semiconductor increases when electromagnetic radiation of wavelength shorter than $1240nm$, is incident on it. The band gap for the semiconductor is:

• A. $2.1eV$
• B. $2.5eV$
• C. $1eV$
• D. $0.7eV$

Answer 1

The correct option is C $1eV$

We know: $E=\frac{hc}{\lambda }$
$\lambda =1240nm$
$E=1.6\times {10}^{-19}$
$E=1eV$